A clutch device having a plurality of rollers disposed on a track formed between an input rotary member and an output rotary member is conventionally known (Patent Literature 1). The clutch device disclosed in Patent Literature 1 is configured so that the rollers are tilted with respect to a plane including a central axis, and that the output rotary member (outer ring) is allowed to move in the axial direction. When the input rotary member (inner ring) relatively rotates in a predetermined direction with respect to the output rotary member (outer ring), the force of the rollers acts to pull the input rotary member and the output rotary member toward each other (the force of decreasing the distance between tracks) moves the output rotary member in the axial direction. This causes the rollers to become engaged, thereby transmitting motive power to the output rotary member. When, on the other hand, the input rotary member relatively rotates in an opposite direction with respect to the output rotary member, the force of the rollers acts to pull the input rotary member and the output rotary member away from each other (the force of increasing the distance between tracks) moves the output rotary member in the axial direction. This causes the rollers to become disengaged, thereby causing the input rotary member and the output rotary member to rotate relatively (rotate freely).